Wax-substituted aryl ether acids and method of making same



Patented Aug. 12, 1941 UNITED STATES PATENT OFFICE vvsx-srms'rrru'rEn ARYL ETHER ACIDS AND METHOD or MAKING SAME Orland M. Reiif, Woodbury, N. J., and Ferdinand P. Otto, Philadelphia, Pa., assignors to Socony- Vacuum Oil Company, Incorporated, New York, N. Y., a corporation of New York No Drawing Application August 26, 1938,

Serial No. 226,910

13 Claims.

This invention relates to the production of certain. new chemical compounds or compositions which may be generally designated as waxsubstituted aryl ether acids. Although the invention is broadly concerned with chemical compounds or compositions coming within the above blended in a minor proportion with viscous mineral oil fractions, such as mineral oil fraction: of the lubricant type, to depress the pour point and improve the viscosity index of the oil. The present invention, however, is not concerned with the mineral oil composition obtained by blending a compound of the type contemplated herein with oil. Such mineral oil compositions form the subject matter of our copending application Serial No. 226,911, filed August 26, 1938 (now Patent 2,198,293), to which reference is made for further details in the composition of these preferred oil-miscible compounds.

It is to be understood, therefore, that while our invention contemplates oil-miscible compounds or ccmpositions of the type referred to above, asa preferred class or group within the general field of invention, the invention is not limited to such oil-miscible compounds or compositions, since the whole class of new materials is possessed of valuable properties irrespective of oil miscibility. For example, these compounds or compositions may be used as intermediaries in invention contemplated herein are effective, when the production of the corresponding'metal salts,

resins, resin-like materials, rubber substitutes, etc. Numerous other uses and applications of the compound or compositions contemplated herein will be readilyapparent to those skilled in the art from the following description of theircomposition and'preferred methods of synthesis.

The compounds or compositions contemplated by this invention may be broadly classified as wax or heavy alkyl substituted aryl ether acids. They may alsobe characterized as hydroxyaromatic (phenolic) compounds in which part of the nuclear hydrogen has been replaced with analiphatic hydrocarbon group or groups derived from a high molecular weight aliphatic or predominantly aliphatic material, and in which the hydroxyl hydrogen has been replaced with an organic aliphatic or aromatic carboxylic acid group, (the aliphatic type comprising fatty'and alicyclic acids; the aromatic comprising benzenoid and heterocyclic acids).

The term heavy alkyl" or wax as used herein in connection with the alkyl substituents on the characterizing aryl nuclei of these other acids is intended to include any pure compound or mixture of compounds predominantly aliphatic in nature and containing at least twenty carbon atoms. Petroleum wax, such as paraffin wax, is

contemplated as one of the preferred sources for this heavy alkyl or wax substituent, but the invention is not limited thereto. It will be understood that when a mixture of aliphatic hydrocarbon compounds, such as those which characterize petroleum wax, is used to provide the heavy alkyl substituent, the resulting composition will be an intimate admixture of compounds, or more specifically, an intimate admixture of aryl ether carboxylic acids which differ from each other with respect to the nature of the alkyl substituent. More specifically, the invention contemplates an intimate admixture of alkyl substituted aroxy-aromatic carboxylic acids or an intimate admixture of alkyl substituted aroxyaliphatic carboxylic acids wherein the acids in a given mixture differ from each other with respect 'to the alkyl substituents which are attached to the aryl nucleus of the aroxy group and are predominantly alkyl groups of at least twenty carbon atoms, correspondingsubstantially to the different aliphatic hydrocarbons in paraflln wax.

In addition to the heavy alkyl or "wax substituent and the ether acid substituent, the characterizing aryl nucleus of the compounds contemplated herein may have additional nuclear hydrogen substituted with other radicals or groups. Taking this into account compounds of the type contemplated herein may be represented by the formulae 11 01.0003 R 0.z;co0H

R- R R R R .R

a R l in which Z represents an aliphatic or an aromatic radical; at least one B represents an alkyl group containing at least twenty carbon atoms and the remaining Rs represent residual hydrogen or'a radical selected from the group consisting of aliphatic hydrocarbon groups having less than twenty carbon atoms, alkoxy, aroxy, aralkyl, aryl, hydroxyl, chlorine, nitro and amino radicals or groups.

In the class of these compounds or products which are preferred for use as oil addition agents it is important that the heavy alkyl (wax) substituent comprise a substantial proportion of the composition as a whole and it appears from the results of our research that there is a critical range in the degree of wax substitution below which the wax-substituted aryl ether acids will not satisfy the requirements for oil miscibility. This critical range in the degree of alkylation or wax-substitution may vary with: (a) the mineral oil fraction in which the product is to be used; (b) the character of the aryl nucleus (monoor poly-cyclic) (c) monoor poly-substitution of the aryl nucleus; and (d) other substituents which may be of positive or negative or of neutral solubilizing activity. In general it may be said that a polycyclic nucleus appears to require a higher degree of alkylation than a mono-cyclic nucleus.

In view of the foregoing variables it would be impracticable to attempt to give an expression and figure which would indicate accurately the proper degree of alkylation or heavy. alkyl substitution satisfying all cases, taking these variables into account. As a'guide for pre'paringthe compound for oil'improving agents our research indicates that alkylation of an aryl hydroxide droxylate thus formed with the corresponding metal soap or salt of the desired halogenated carboxylic acid. The alkylated aryl ether carboxylic acid is finally obtained by acidifying the last obtained product with a mineral acid. Another desirable procedure for obtaining waxaroxy-aliphatic acids is to use an ester of the aliphatic acid, instead of the metal soap or salt, and recover the acid by saponification of the final condensation product. In obtaining waxaroxy-aromatic carboxylic acids it is preferable I to use the alkali salt of a brom aromatic acid with paraflin wax, to obtain the initial reactant,

should be so controlled that the ratio by weight of aryl hydroxide to alkylated aryl hydroxide is not greater than about .20 or twenty percent when the weight of the aryl hydroxide component is expressed in terms of its chemically equivalent weight of phenol (CsHsOH) This ratio (which we may term the ph enolic hydrogen oi the alkyl substituted aryl hydroxide is then substituted with an aliphatic or aromatic carboxylic acid group.

ratio) of twenty percent, represents what we I Typical hydroxyaromatic compounds or aryl hydroxides which may be used as starting material are: phenol, resorcinol, hydroqulnone,

catechol, cresol, xylenol, hydroxydiphenyl, benlustrative examples.

in the formation of aryl ether acids are: the

monobasic acids such as acetic, butyric, octoic, palmitic, stearic, naphthenic, etc.; poly-basic acids such as maleic, succinic, adlpic, etc.; aromatic acids such as benzoic, phthalic, cinnamic, furoic, etc. Both the aliphatic and aromatlctype acids may also carry substituents such as keto, nitro, amino, and hydroxy groups.

If it is desired to obtain a product having an aroxy or alkoxy substituent in the characterizing aryl nucelus it is preferable to start with an aryl hydroxide containing such a substituent group and effect the alkylation thereof with a high molecular weight unsaturated aliphatic hydrocarbon having a carbon chain length of at least twenty carbon atoms (such as eicosylene, cerotene, melene, etc.) or a higher alcohol having at least twenty carbon atoms (such as ceryl alcohol, myricyl alcohol, etc.) using I-IzSOrv as a catalyst.

When it is desired to obtain a nitro or amino group as an additional substituent in the characterizing aryl nucleus, the aryl hydroxide is alkylated when free of nitro or amino groups and such alkylation is followed by nitration to introduce the nitro substituent. The amino group can be obtained by reduction of the nitro p.

Further details in the procedures which may be followed in making the compositions of this invention may be obtained from the following il- PREPARATION OF WAX-SUBSTITUTED PHENOXY -AL1PHATIC CARBOXYLATE SALTS (1) ALKYLATION or Pruner.

' terial.

' 600 grams oi mineral oil (Say. Vis. 244 sec; at

chlorwaxP-Yformed ischlorine. A quantity or chlorwaxr thus obtained, containing three atomic proportions of chlorine, is heated to a temperature varying from just above its melting point to not over 150 F., and one mole of phenol (CsHOH) is admixed therewith. The mixture is heated to about 150 F., and a quantity of anhydrous aluminum chloride corresponding to about three per cent of the weight of chlorwax in the mixture is slowly added to the mixture with active stirring. The rate of addition of the aluminum chloride should be sufliciently slow to avoid violent foaming, and during such addition the temperature should be held at about 150 F. After the aluminum chloride has been added, the temperature of the mixture may be increased slowly over a period of from fifteen to twenty- ,five minutes to a temperature of about 250 F. and then may be more slowly increased from about 300 F. to'about 350 F. If the emission of HCl gas has not ceased when the final tem- 130 F.) and reacted with 6 grams of sodium as sodium ethylate at 300 F. during a one-hour period, allowing the alcohol to distill to complete the formation of sodium phenate.

(3) FORMATION or Emma A011) SALTS non Wax- ALKALI METAL PHENATE Example a-War-phenorcu-acetic acid 100 F; This sodium chloracetate suspension was then added to the solution of-wax sodium phenate, in mineral oil, and the reaction mixture was held at 150 F.'during a two-hour period to form the wax-substituted phenoxy sodium acetate.

hydrochloric acid to liberate the free ether acid,

perature is reached, the mixture may be held at 300 or 350 F, for a, short time to allow completion of the reaction. But, to avoid possible cracking of the wax, the mixture should not be heated appreciably about 350 F., nor should it be held .at that temperature for any extended length of time.

It is important that all unreacted or nonalykylated hydroxyaromatic material (phenol) remaining after the alkylation'reaction be removed. Such removal can be effected generally 7 chlorine (twenty per cent chlorine in the chlor-- wax) is reacted with one mole of phenol, may, for brevity herein, be designated as wax-phenol (ii-20). Parenthetical expressions of this type (A- B) will be used hereinafter in connection with the alkylated hydroxyaromatic compounds to designate (A) the number of atomic proportions of chlorine in chioraliphatic material reacted with one mole of hydroxyaromatic compound in the Friedel-Crafts reaction, and (B) the chlorine content of the chlor-aliphatic ma- In' the above example A=3 and 18:20. This same designation will also apply to the metaloxyaromatic-metal carboxylate derivatives.

Wax-phenol (3-20) as obtained by the above procedure had a phenol content or a "phenolic and is purified by water-washing the product to remove reaction salts. The product thus obtained is then dried to give a concentrated mineral oil blend of the wax-phenoxy acetic acid. The pure undiluted acid can be obtained by use of light mineral oil such as kerosene distillate as diluent in place of the heavier distillate suggested above whereby the pure acid concentrate can be obtained by distillation of the kerosene diluent.

Example b-Wdx-phenaxy-benzoic acid 100 grams of wax phenol was reacted with 2.95 grams of metallicsodium in the presence or 5% by volume of anhydrous amyl alcohol at a temperature of 300 F. during a one hour period,

allowing the alcohol to distill. The wax sodium phenate. thus formed was then mixed with 28.9

grams of brom-sodium'benzoate and the mixture for a period of about four hours; The product ratio" of about sixteen per cent. Our research indicates that this phenolic ratio in the neigh-' borhood of'sixteen per cent may be considered as representing'about the maximum for satisfactory miscibility and in viscous oils of the aryl ether acid derivatives of alkylated hydroxyaromatic compounds in which the alkyl substituent (2) FORMATION OF WAX-SUBSTITUTED ALKALI on ALKALINE EARTH METAL PHENATE As an example of thisstep in the preparation of our oil-improving agents, 200 grams of wax phenol (12.2% combined phenol) is diluted with oifthis reaction was the sodium salt of wax phenoxy benzoic acid. The free acid was obtained by neutralizing the reaction product'of the foregoing step with aqueous hydrochloric acid, followed by water washing and drying to obtain the finished product.

Wax-substituted aryl ether acids of the general character described above can be-prepared from other wax-substituted hydroxyaromatic compounds, either monoor poly-cyclic and substituted or unsubstituted, such, for example, as wax-naphthol (314) having a combined naphthol content of sixteen per cent and equivalent phenolic content or phenolic ratio" 01310.4 per substituents than petroleum wax, although, as

. indicated above, alkylated hydrocarbons of the which with the phenolic ratio properly controlled wax type (having at least twenty carbon atoms) are preferred. It is also emphasized that, the

invention is not limited to products obtained from acetic or benzoic acid as a source for the ether acid substituent-but that any halogenated organic acid may be used in the reactions described above to obtain various ether acid substituents. I

Wax-aryl ether acids of the type described above are highly viscous rubber-like products.

are readily soluble in mineral oils. Their color is such that they can be readily blended with light-colored mineral oilfractions without sub- The mixture is then neutralized with dilute stantial darkening of the oil, which makes them particularly desirable for use in this connection. As will appear from the foregoing description,

the compounds or products may be broadly demay be characterized as alkyl or wax-substituted-aroxy-aromatic-carboxylic' acids. These complex ether acids may also be defined as alkylated or wax-substituted hydroxyaromatic compounds in which the hydroxyl hydrogen has been substituted with an organic acid group, it being understood that the terms alky and alkylated are used herein in a broad sense to include polyatomic or polyvalent, as well as monovalent aliphatic radicals or groups; also that the term "wax as used herein is used broadly to designate aliphatic or predominantly aliphatic materials having at least twenty carbon atoms.

We claim:

1. As a new composition of matter, an alkylsubstituted aryl ether carboxylic acid in which the alkyl substituent contains at least twenty carbon atoms, the said product possessing the property of depressing the pour point and improvingthe viscosity index of a mineral oil when admixed therewith in a minor proportion.

2. As a new composition of matter, an alkylsubstituted aryl ether carboxylic acid in which the alkyl substituent contains at least'twenty carbon atoms and is derived from paraflin wax, the said product possessing the property of depressing the pour point and improving the vis-' cosity index of a mineral oil when admixed therewith in a minor proportion.

3. As a new composition of matter, an alkyltwenty carbon atoms and is attached to the sponding substantially to the difierent aliphatic hydrocarbons contained in paraflin wax.

7. As a new composition of matter, an intimate mixture of alkyl-substituted phenyl ether carboxylic acids, said acids differing from each other with respect to the nature of the alkyl substituent, the said alkyl substituent being attached to the phenyl nucleus and the difierent alkyl substituents being predominantly alkyl groups of at least twenty carbon atoms, and having a composition corresponding substantially to the different aliphatic hydrocarbons contained in parafl'in wax.

8. As a new composition of matter, an intimate mixture of alkyl-substituted phenoxy-aliphatic-carboxylic acids, said acids differing from each other with respect to the nature of the alkyl substituent, the said alkyl substituent being attached to the phenyl nucleus of the phenoxy group and the difierent alkyl substituents beingpredominantly alkyl groups of at least twenty carbon atoms, and having a composition corresponding substantially to the different aliphatic hydrocarbons contained in paraflin wax.

9. As a new composition of matter, an intimate mixture of alkyl-substituted phenoxy-acetic acids, said acids diil'ering from each other with respect to the nature of the alkyl substituent, the said alkyl substituent being attached to the phenyl nucleus of the phenoxy group and the difierent alkyl substituents being predominantly group and the different alkyl substituents being aroxy nucleus, the said product possessing the" property of depressing the pour point and improving the viscosity index or a mineral oil when.

gimate mixtureof alkyl-substituted aroxy-aliphatic carboxylic acids, said acids diflerlng from each other with respect to the nature of the alwl substituent, the said alkyl substituent being attached to the'aryl nucleus of the aroxy group and the diflerent alkyl substituents being predominantly alkyl groups of at least twenty carbon atoms, and

- having a composition corresponding substantially to the diflerent aliphatic hydrocarbons contained in paramn wax.

6. As a new composition 01 matter, an intimate mixture of alkyl-substituted aroxy-aromatlc carboxylic acids, said acids diflering from each otherwith respect to the nature of the alkyl substituent, the said alkyl substituent being attached to the aryl nucleus of the aroxy group and the different alkyl substituents being predominantly alkyl groups or at least twenty carbon atoms, and having a composition correpredominantly alkyl groups of at least twenty carbon atoms, and havinga composition corresponding substantially to the difierent aliphatic hydrocarbons contained in paraflin wax.

11. As a new composition 01' matter, an intimate mixture or alkyl-substituted phenoxy-benzoic acids, said acids differing from each other with respect to the nature of the alkyl substituent, the said alkyl substituent being attached to the phenyl nucleus of the phenoxy group and the difierent alkyl substituents being 'predominantly alkyl groups of at least twenty carbon atoms, and having a composition corresponding substantially to the difierent aliphatic hydrocarbons contained in paramn wax.

12. Asa new composition of matter, an intimate mixture of alkyl-substituted aryl ether carboxylic acids, said acids differing from each other with respect to the nature of the alkyl substituent, the said substituent being attached to the aryl nucleus and the difierent alkyl substrtuents being predominantly alkyl groups of at least twenty carbon atoms, and having a composition corresponding substantially to the differ- 'evrgtx aliphatic hydrocarbons contained in paraflin 13. 'Ihe method of synthesizing oil-miscible petroleum wax-aryl-ether acids which includes: reacting a chlorinated wax with a hydroxyaromatic compound in proportions such that the resulting wax-hydroxyaromatic. compound has a hydroxyaromaticcontent not greater than the equivalent otabout twenty per cent phenol; substitutin the hydroxyl hydrogen with a metal sesalt of a wax-aryl-ether acid; and neutralizing iected from the group consisting oi? alkali and said last mentioned salt with a mineral acid to alkaline earth metals to form the corresponding .form the wax-aryl-ether acid.

'waxaryl-metal oxide; reacting the wax-aryl- ORLAND M. REIFF.

metal oxide with the alkali metal salt of a hal- 5 FERDINAND P. OTI'O.

ogenated organic acid to form the corresponding Patent to. 2,2 2, 666

CERTIFICATE OF CORRECIIICN.

August 12, 19in. ORLAND n. REIFF, ET AL.

It is berebycertified that error appears in the printed specification I of'the above numbered patent requiring corre'cti on as follows: Page LL, sec- 0nd column, line 70, strike out "petroleum" and insert the same after '.-''chloi'1nated in line 71, same claim; and that the said Letters Patent should be read with this eorrection therein that the same may conform to fi1e,.record of the case in the Patent Office.

Signed and-sealed this 10th day of Febrilary, A. D. 19LL2.

v Henry Van Arsdale, (Seal) Acting Commissioner of Patents. 

